This study attempts to manufacture a Ni-Cr-Al-Y coating layer using a kinetic spray process and investigates the microstructure and physical properties of the manufactured layer. The Ni-22Cr-10Al-1Y (wt.%) composition powder is used, and it has a spherical shape with an average diameter of 23.7 μm. Cu plate is used as the substrate. Optical microscope, X-ray diffraction, scanning electron microscope and Vickers hardness test are carried out to characterize the macroscopic properties of the coating layer. Furthermore, the coating layer underwent vacuum heat treatment at temperatures of 400˚C and 600˚C for 1 hour to check the effect of heat treatment temperature on the properties. The manufactured coating layer is 1.5 mm thick, and featured identical phases to those found in the powder. The porosity of the coating layer is measured at 2.99%, and the hardness is obtained at 490.57 Hv. The layer shows reduced porosity as heat treatment temperature increased, and hardness is reduced at 400˚C but shows a slight increase at 600˚C. Based on the findings described above, this study also discusses possible manufacturing methods for a Ni-Cr-Al-Y coating layer using the kinetic spray process.

Background : The organic matter content of land clearing or soil brought from an other place is very low, less than 0.5%. However, the organic matter content of natural habitat soil and leader farmhouse soil was two to three times higher than that of general farmhouse soil. As a result, the yield of Gastrodia elata was higher than that of general farmhouse. Therefore, this experiment was carried out to investigate the yield of G. elata according to the application of green manure crops (GMCs). Methods and Results : This experiment was carried out in a soil with organic matter content of 0.5% in rain shelter greenhouse. The kind of GMCs are corn, Sudan grass, sorghum and oats, and the throughputs per 10 a were 2,000 ㎏, 2,200 ㎏, 1,500 ㎏ and 700 ㎏ of each. The soil preparation was carried out after treated of GMCs at least one month before G. elata was formally planted. As the results of these experiment, organic matter content in soils increased 4 - 5 times compared with before treatment. As a result, the yield of G. elata increased by 21 - 41% in all treatments of GMCs. In addition, there was 2 - 5% more G. elata of good merchantable quality. However, the soil temperature in the summer season period of 2016 (7.1 - 8.31) was 1.2 - 1.6℃ higher than the previous year. The day when the outside temperature was above 30℃ was 41 days. It doubled from the previous year. Soil moisture content showed similar tendency according to treatments. As a result, 20 - 30% of high temperature damage and 20 - 50% of putrefaction occurred, and the total yield also decreased by 20 - 30% compared to normal year. Conclusion : In conclusion, some organic matter is needed for cultivation of G. elata. Therefore, it is considered that it would be better to keep the organic matter content at 2 - 3% when the destination are managed, and to use corn or Sudan grass as the GMCs.